The purpose of the contract is to support a five year program to establish and maintain a registry of clinical information on U.S. residents affected by primary immunodeficiency diseases. The expected outcomes include: 1) improved access of investigators to patients for both basic studies and clinical trials; 2) provision of accurate and up to date information useful to clinicians and genetic counselors; 3) improved access of affected individuals to the latest therapy; and 4) establishment of a database which can be used to determine the socioeconomic costs of these diseases. Research in several areas will be advanced by this resource include immunodeficiency, host defense against infection, inflammation, and autoimmune diseases.